Adjustable mobile ladder



June 17, 1952 ADJUSTABLE MOBILE LADDER- Filed March. 28, 1947 4 Sheets-Sheet 1 u 2 I 4 6 l 6.2 l5 5 /z 66 46 I 5% i Inventor l I 65 55 H 0 waning? @3591 Attorneys June 17, 1952 H. w. 'RIESER 2,600,807

ADJUSTABLE MOBILE LADDER I Filed March 28, 1947 4 Sheets-Sheet 2 June 17, 1952 H. w. RIESER 2,600,807

Y ADJUSTABLE MOBILE LADDER Filed March 28, 1947 4 Sheets-Sheet 3 Inventor Altorneys June 17, 1952 H. w. RIESER ADJUSTABLE MOBILE LADDER 4 Sheets-Sheet 4 Filed March 28, 1947 filly!!! u fi warazli fizkser Patented June 17, 1952 UNITED STATES PATENT OFFICE ADJUSTABLE MOBILE LADDER Howard W. Rieser, Harpster, Ohio Application March 28, 1947, Serial No. 737,740

2 Claims.

This invention relates to an improved construction of an adjustable ladder and wheeled support especially adapted for use in the harvesting of fruit or the like from trees and has particular reference to a ladder structure for supporting a person engaged in harvesting fruit from a tree and which may be readily adjusted for positioning the ladder in any desired location with respect to the tree so that fruit located adjacent the ends of branches will be readily accessible to a picker supported by the ladder.

More particularly it is an aim of the present invention to provide an adjustable ladder having a substantial wheeled frame which may be readily anchored to the ground by the weight of the ladder, for securely maintaining the ladder in a predetermined position.

Still another object of the invention is to provide a ladder and support which is so constructed that the supporting frame thereof may be anchored in a desired position for locating the base of a ladder and the ladder thereafter adjusted relatively to the support for positioning the upper portion thereof in a desired location in a tree.

Still another object of the invention is to provide a support having means for accomplishing transverse tilting thereof for transversely adjusting the upper portion of the ladder relatively to the support and/or for leveling the ladder when the mobile support is located on uneven ground.

Various other objects and advantages of the invention will hereinafter become more fully apparent from the following description or drawings, illustrating a preferred embodiment thereof, and wherein:

Figure 1 is a side elevational view showing the adjustable ladder in its elevated position;

Figure 2 is an enlarged horizontal sectional view taken substantially along a plane as indicated by the line 2-2 of Figure 1;

Figure 3 is a longitudinal vertical sectional view taken substantially along a plane as indicated by the line 3-3 of Figure 2;

Figure lis a cross sectional view of the ladder and support, taken substantially along a plane as indicated by the line 4-4 of Figure 3;

Figure 5 is an enlarged sectional view taken substantially along a plane as indicated by the line 5--5 of Figure 2;

Figure 6 is an enlarged longitudinal sectional view of the forward end of the supporting frame and showing a portion of the ladder engaged thereby and in the position that it will assume when folded against the frame for normal transportation or storage;

Figure 7 is a detailed longitudinal sectional view of a portion of the wheeled frame;

Figure 8v is a front elevational view showing the ladder detached from its wheeled support;

Figure 9 is an enlarged horizontal sectional View taken substantially along a plane as indicated by the line 99 of Figure 4, and

Figure 10 is a vertical sectional view taken substantially along a plane as indicated by the line |0I0 of Figure 9.

Referring more specifically to the drawings, the adjustable, mobile ladder in its entirety is lesignated generally II and comprises a wheeled supporting means, designated generally l2 and a ladder [3 which is adjustably supported thereby for swinging movement, relatively to the wheeled frame [2 in a direction substantially parallel to the longitudinal axis thereof, and for transverse rocking movement, with the supporting frame l2, in a direction substantially at right angles to the direction of swinging movement of said ladder.

The wheeled supporting frame ll comprises a pair of forwardly converging longitudinal beams l4 which are connected and joined at their forwards ends by a plate i5 which is provided with a depending spike it which extends to below the bottom edges of the beams l4 and which is adapted to extend into' the ground, as seen in Figure 6, to provide a support and anchor for the forward end of the frame of the wheeled support l2. As seen in Figure 2, the beams M are connected intermediate of their ends by a transverse brace I1 and said beams are anchored adjacent their rear ends, as seen in Figures 2 and l, to an axle 18 which projects therebeyond and which is provided at each end thereof with a fixedly connected frame l9. One of said frames i9 is provided with astub-axle 20 projecting outwardly therefrom and on which a ground engaging wheel 2|, equipped with a pneumatic tire is journaled.

A housing 22, as best seen in Figure 9, has one side thereof fixed to a projection 23 which extends outwardly from the other frame [9 and said housing contains a rack bar 24 which is disposed for movement vertically thereof and which is provided with a stub-axle 25 which projects through a vertically disposed slot 26 in the other, outer wall of the housing 22 and on the outer end of which a second wheel 2| is journaled. As seen in Figures 9 and 10, a shaft 21 is journaled transversely, in the housing 22 and has a pinion 28 keyed thereto and which meshes with the teeth of the rack bar 24. A worm gear 29 is also keyed to the shaft 21 and is disposed within the housing 22 and meshes with a worm 30 which is provided on the end of a shaft 3|, which shaft is journaled in a bearing 32 formed in one end wall of the housing 22. As seen in Figures 1 and 2, the shaft 3| extends rearwardly of the axle I8 and is provided with a crank 33 at its rear end by means of which said shaft 3| can be manually revolved for raising and lowering the rack bar 24 for raising and lowering the wheel 2 I, connected thereto, relatively to the axle I8 and to the remainder of the supporting frame II.

The supporting frame I I also includes a pair of laterally spaced handles 34 which are secured at corresponding ends thereof by fastenings 35 to the beams I4, adjacent the rear ends thereof and behind and beneath the axle I8. The handles 34 extend upwardly and rearwardly from the beams I4 and terminate at their upper ends in downwardly turned hand grips 36, as best seen in Figure 3. The handles 34 are braced relatively to the beams I4, each by a brace 31 which is connected thereto, intermediate of the ends of the handle 34 and which extends forwardly and downwardly therefrom and is connected at its opposite end to the complementary beam I4, forwardly of and adjacent the cross beam or brace I'I.

As best seen in Figure 4, the braces 31 are also connected, intermediate of their ends, to upright standards 38 by fastenings 39 which extend transversely therethrough, The standards 38 are formed integral with or fixedly secured to the axle I8, and 81a fastenings 39, one of which is provided for each of said standards, also extend through the side rails 45 of the ladder I3, adjacent the lower ends thereof, and provide means for pivotally supporting the ladder I3 on the sup porting frame I I.

As best seen in Figure 4, the axle I8 is provided with a plurality of longitudinally spaced bearings 4| which rise therefrom, between the standards 38 for iournaling a shaft 42 which extends through an opening 43' in the standard 38, which is disposed remote to the housing 22. The shaft 42, between said standard 38 and the adja cent frame I9, extends into a gear case 44 which is likewise mounted on the axle I8, as best seen in Figure 5. A worm gear 45 is disposed within the housing or case 44 and is keyed to the shaft 42 and meshes with a worm 46 which is likewise journaled in the gear case 44, above and transversely of the shaft 42 and which forms a part of the shaft 41 which extends rearwardly from the gear case 44 and which terminates in a crank 48.

A pair of bars 49 are pivotally connected by pintles 50, one to each of the rails 40 of the ladder I3, said pintles- 50 being disposed in transverse alignment. A flexible member or cable is connected to the lower end of each bar 49 and said cables 5| converge downwardly therefrom and are connected at their opposite ends to one end of a flexible member or cable 52 by a swivel or connecting member 53. The opposite end of the cable or flexible member 52 is anchored to and wound on the shaft 42 between the intermediate bearings 4| and said cable 52 is trained under a pulley 54 which is fastened to the upper side of the brace I'I, intermediate of the ends thereof, by an eye bolt and nut fastening 55. A pair of bars 56 are pivotally connected by pintles 51 to the rails 40 of the ladder I3 and substantially above the bars 49. Each of the bars 56 has a flexible member or cable 58 secured thereto and depending therefrom and which is connected at its opposite end by a coupling 59 to one end of a flexible member or cable 60. The two cables 60 each have their opposite end wound on the shaft 42 between the intermediate and outermost bearings 4| and said last mentioned ends of the cables 60 are anchored to the shaft 42 and wound thereon in the opposite direction to the cable 52. The cables 69 are each trained under a pulley 6|, each of which pulleys is connected by a clamp 62 to one of the handles 34.

The flexible members 5|, 52 and 58, 60 are so arranged as to be disposed substantially taut regardless of the position of the ladder I3 relatively to the wheeled support I2 and it will be readily apparent that when the crank 48 is revolved in a direction, for example, for rotating the shaft 42 clockwise as seen in Figure 3, that the cable 52 will be payed off of said shaft at the same rate of speed as the cables 60 are wound thereon, so that the ladder ill will be swung upwardly or toward a vertical position on its pivots 39, which are disposed above and in vertical alignment with said shaft 42. Likewise, when the shaft 42 is revolved in the opposite direction by the turning of the crank 48 in the opposite direction, the cable 52 will be wound onto the shaft 42 as the cables 63 are payed off of said shaft to allow the ladder I3 to swing toward a horizontal position or counter-clockwise, and in either movement of the ladder the cables or flexible connections 5| 52 and 58, will be held taut to thereby securely hold the ladder substantially rigid with respect to the supporting structure I2 in any position to which it is moved.

For transportation and storage, the ladder is swung counter-clockwise until the intermediate portion thereof is located adjacent the plate I5, as seen in, Figure 6, and a hook 63 is engaged over one of the rungs 64 of the ladder I3 and is secured to the wheeled support I2 by th threaded shank of said hook 63 which extends through the plate I5 and is connected detachably thereto by a nut 65, which engages said threaded shank. In this position, it will be readily apparent that the mobile adjustable ladder II is in a most convenient position for storage or transportation.

In the conventional use of the ladder, the ladder I3 is elevated to substantially a vertical position and the supporting structure I2 is then disposed near the base of a tree in which the ladder is intended to be disposed and the forward end of the support is forced downwardly to anchor the spike I6 in the ground for anchoring the wheeled support I2 in its desired location. The ladder I3 is then swung clockwise, as seen in Figure 1', by operation of the crank 48, for positioning the upper portion of the ladder in any desired position in the tree. Likewise, the position of the upper portion of the ladder may be angularly adjusted in a direction transversely of the longitudinal axis of the wheeled frame I2 by operation of the crank 33, as previously described, for raising and lowering the wheel 2| which is connected to the stub-axle 25, relatively to the axle I8, or such adjustment may be made for leveling the wheeled support I2 as where it is located on uneven ground. Flexible retaining members 66 are anchored to the handles 34 and detachably engaged with the cranks 33 and 48 to retain said cranks and the parts actuated thereby in adjusted positions, one of the members 66 being shown disengaged in Figure 1.

Various modifications and changes are contemplated and may obviously be resorted to, without departingfrom the spirit or scope of the inven tending from opposite sides thereof and each connected to a common manually operated winding and unwinding means disposed directly beneath the ladder pivot on said support for swingably raising and lowering the ladder relatively to the support and for retaining the ladder substantially rigidly with respect to the support in various justed positions.

2. An adjustable ladder of the character described comprising an elongated frame, a ladder having one end pivotally mounted on'the frame for swinging movement in a direction lengthwise of the frame and in substantially a vertical plane, a shaft journaled on said frame transversely thereof and beneath and in substantially vertical alignment with the pivoted end of the ladder, manually actuated means for revolving said shaft in either direction, flexible members anchored to said shaft and wound thereon in opposite directions and extending therefrom longitudinally of the frame and toward opposite ends thereof, pulleys secured to the frame in longitudinally spaced relationship to said; shaft and around which said flexible members are trained, and said flexible members extendingiip wardly from said pulleys on opposite sides of the ladder and being connected to the ladder at spaced points intermediate the ends thereof whereby when said shaft is revolved in either direction one of said flexible members will be wound thereon and the other will be unwound therefrom for either raising or lowering the ladder relatively to the supporting frame, and said 1 flexible members being arranged relatively to the supporting frame to be retained substantially taut in a plurality of angular positions of the lad- :der relatively to the wheeled supporting frame for substantially rigidly retaining the ladder in a plurality of elevated positions.

: HOWARD W. RIESER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 20,752 Welte June 29, 1858 193,960 Hoyt Aug. 7, 1877 268,612 Bower Dec. 5, 1882 445,487 Arnold Jan. 27, 1891 545,643 Cairnes Sept. 3, 1895 580,295 Swenson Apr. 6, 1897 194,486 Briggs July 11, 1905 937,388 Smith Oct. 19, 1909 1,133,631 Gerding Mar. 30, 1915 1,423,046 Taber July 18, 1922 1,691,732 Nichels Nov. 13, 1928 FOREIGN PATENTS Number Country Date 166,690 Germany Dec. 23, 1905 

